Functionalized polyolefin capillaries for open tubular ion chromatography

Abstract

Open tubular capillary columns for liquid and ion chromatography, based upon an ionically impermeable polyolefin capillary having a bore with a sulfonate-group- or amine-group-functionalized internal surface. The capillary columns may include a coating of ion exchanging nanoparticles electrostatically bound to the functionalized internal surface. The capillary columns may be made by exposing the interior surface to a sulfonating reagent comprising chlorosulfonic acid (ClSO3H), preferably from 85 wt % to 95 wt % chlorosulfonic acid at a process temperature of 20 to 25° C. The interior surface may be subsequently exposed to an asymmetrical diamine to form a sulfonic mid-linkage to the diamine, i.e., to form a sulfonamide-linked, amine-group-functionalized internal surface. The coating may be provided by subsequently exposing the interior surface to an aqueous suspension of ion exchanging nanoparticles to electrostatically bond the ion exchanging nanoparticles to the functionalized internal surface.

What is claimed is: 
     
       1. An open tubular capillary column for liquid and ion chromatography, the column comprising:
 an ionically impermeable capillary of a polyolefin material; 
 the capillary having a bore with an internal surface that has been exposed to a sulfonating reagent comprising chlorosulfonic acid (ClSO 3 H) to sulfonate the polyolefin material to a sulfonated polyolefin material, wherein, after exposure to the sulfonating reagent, the internal surface has been exposed to an asymmetrical diamine aminating agent to form a sulfonamide-linked, amine-group-functionalized internal surface. 
 
     
     
       2. The open tubular capillary column of  claim 1 , wherein the aminating reagent comprised N—N-dimethylethylenediamine. 
     
     
       3. The open tubular capillary column of  claim 1 , wherein, after exposure to the aminating agent, the internal surface has been exposed to a methylating agent to form a sulfonamide-linked, quaternary-amine-group-functionalized internal surface. 
     
     
       4. The open tubular capillary column of  claim 1 , wherein the bore further includes a coating formed by exposing the sulfonamide-linked, amine-group-functionalized internal surface to a solution of suspended cation exchanging nanoparticles. 
     
     
       5. The open tubular capillary column of  claim 4 , wherein the suspended cation exchanging nanoparticles are sulfonate-group- or carboxylate-group-functionalized latex nanoparticles. 
     
     
       6. A process for manufacturing an open tubular capillary column for liquid and ion chromatography, the process comprising:
 exposing an internal surface of a capillary tube manufactured from a polyolefin material to a sulfonating reagent including chlorosulfonic acid to sulfonate the polyolefin material. 
 
     
     
       7. The process of  claim 6 , wherein the sulfonating agent comprises from 85 wt % to 95 wt % chlorosulfonic acid, and the internal surface is exposed to the sulfonating agent for at most 8 hours. 
     
     
       8. The process of  claim 6 , further comprising exposing the sulfonated internal surface of the capillary tube to a nonaqueous, chlorosulfonic acid compatible flushing agent. 
     
     
       9. The process of  claim 8 , further comprising rinsing the flushed and sulfonated internal surface of the capillary tube with deionized water. 
     
     
       10. The process of  claim 8 , further comprising:
 after exposure to the flushing agent, exposing the sulfonated internal surface of the capillary tube to a suspension of anion exchanging nanoparticles to electrostatically bond the anion exchanging nanoparticles to the sulfonated internal surface. 
 
     
     
       11. The process of  claim 8 , further comprising:
 after exposure to the flushing agent, exposing the sulfonated internal surface of the capillary tube to an asymmetrical diamine aminating agent to form a sulfonamide-linked, amine-group-functionalized internal surface. 
 
     
     
       12. The process of  claim 11 , wherein the asymmetrical diamine aminating agent comprises N—N-dimethylethylenediamine. 
     
     
       13. The process of  claim 12 , further comprising:
 after exposure to the aminating agent, exposing the internal surface of the capillary tube to a methylating agent to form a sulfonamide-linked, quaternary-amine-group-functionalized internal surface. 
 
     
     
       14. The process of  claim 13 , wherein the methylating agent is methyl iodide or dimethyl sulfate. 
     
     
       15. The process of  claim 13 , further comprising:
 after exposure to the aminating agent, exposing the internal surface of the capillary tube to a suspension of cation exchanging nanoparticles to electrostatically bond the cation exchanging nanoparticles to the amine-group-functionalized internal surface. 
 
     
     
       16. An open tubular capillary column for liquid and ion chromatography, the column comprising:
 an ionically impermeable polyolefin capillary; 
 the capillary having a bore with a sulfonamide-linked, amine-group-functionalized internal surface. 
 
     
     
       17. The open tubular capillary column of  claim 16 , wherein the amine-group-functionalized internal surface provides a quaternary amine group. 
     
     
       18. The open tubular capillary column of  claim 16 , wherein the bore further includes a coating of cation exchanging nanoparticles electrostatically bound to the amine-group-functionalized internal surface. 
     
     
       19. The open tubular capillary column of  claim 18 , wherein the cation exchanging nanoparticles are comprised of sulfonate-group- or carboxylate-group-functionalized latex nanoparticles. 
     
     
       20. The open tubular capillary column of  claim 18 , wherein the cation exchanging nanoparticles form a monolayer over the sulfonamide-linked, amine-group-functionalized internal surface. 
     
     
       21. The open tubular capillary column of  claim 16 , wherein capillary has a sulfonate-group-functionalized region disposed under the internal surface of the bore. 
     
     
       22. The open tubular capillary column of  claim 16 , wherein the polyolefin material comprises a cycloolefin polymer. 
     
     
       23. The open tubular capillary column of  claim 22 , wherein the polyolefin material comprises a norbornene-type polymer.